1986

@article{Gabel1986,
author = {Gabel, V. P. and Birngruber, R. and Lorenz, B.},
title = {Clinical relevance of a dosage device for laser photocoagulation},
journal = {Klin Monbl Augenheilkd},
volume = {188},
number = {4},
pages = {263-5},
note = {Gabel, V P
Birngruber, R
Lorenz, B
GERMANY, WEST
Klin Monbl Augenheilkd. 1986 Apr;188(4):263-5.},
abstract = {Fundus reflectometry constitutes a procedure with which dosage can be precisely regulated during the coagulation process. During retinal coagulation, for example, it is possible with this method to administer coagulations of uniform intensity regardless of variations in either the quality of the fundus image or the absorption of the pigmented structures. This can be useful for coagulation procedures which have to be confined for the most part to the pigment epithelium, as for example in the treatment of central serous retinopathy or in panretinal photocoagulation, where the functional therapeutic principle is still not clearly understood. Another area of application for reflectometric laser coagulation will be laser trabeculoplasty, in which barely detectable lesions have to be placed in the trabecular meshwork.},
keywords = {*Computers
Diabetic Retinopathy/surgery
Humans
*Laser Therapy
Pigment Epithelium of Eye/surgery
Retinal Detachment/surgery
Retinal Diseases/*surgery
Retinal Vein/surgery
Trabecular Meshwork/surgery
AutoPhoN},
ISSN = {0023-2165 (Print)
0023-2165 (Linking)},
DOI = {10.1055/s-2008-1050625},
url = {http://www.ncbi.nlm.nih.gov/pubmed/3723965},
year = {1986},
type = {Journal Article}
}

@inproceedings{Schlott2009,
author = {Schlott, Kerstin and Langejürgen, Jens and Bever, Marco and Koinzer, Stefan and Birngruber, Reginald and Brinkmann, Ralf},
title = {Time resolved detection of tissue denaturation during retinal photocoagulation},
editor = {7373, Proc. SPIE},
pages = {73730E-73730E},
note = {10.1117/12.831877},
abstract = {The retinal photocoagulation is an established treatment method for different retinal diseases. The extent of the thermal coagulations depends strongly on the generated temperature increase. Until now the dosage is based on a pool of experience of the treating physicians as well as the appearance of the whitish lesions on the retina. The temperature course during photocoagulation can be measured in real-time by optoacoustics. A frequency-doubled Q-switched Nd:YLF laser (523nm, 75 ns) is used for optoacoustic excitation and a continuous-wave Nd:YAG laser (532nm) with adjustable irradiation time and power for heating of the fundus tissue. The onset of coagulation is determined by a photodiode that is placed directly behind enucleated porcine eyes, which served as a model. The onset of coagulation is observed clearly when scattering sets in. The required power for coagulation increases exponentially with decreasing irradiation time. The first results on rabbit eyes in vivo indicate that the onset of coagulation defined by just barely visibile lesions at a slit lamp sets in at an ED50 threshold temperature of 63°C for an irradiation time of 400 ms. In conclusion, optoacoustics can be used to determine temperatures during retinal laser treatments in real-time. This allows evaluating the time-temperature-dependence of retinal coagulation in vivo.},
keywords = {AutoPhoN},
url = {http://dx.doi.org/10.1117/12.831877},
type = {Conference Proceedings}
}

Kandulla, J and Elsner, H and Hilmes, M and Hartert, C and Brinkmann, R:
Optoacoustic temperature determination at the fundus of the eye during Transpupillary Thermotherapy.
in Proc SPIE,
no. 5688,
pp. 208-214,

@inproceedings{Schlott2011,
author = {Schlott, Kerstin and Koinzer, Stefan and Ptaszynski, Lars and Luft, Susanne and Baade, Alex and Bever, Marco and Roider, Johann and Birngruber, Reginald and Brinkmann, Ralf},
title = {Optoacoustic temperature determination and automatic coagulation control in rabbits},
booktitle = {Ophthalmic Technologies XXI },
editor = {Ho, Fabrice Manns; Per G. Söderberg; Arthur},
publisher = {Proc. SPIE},
volume = {7885},
note = {10.1117/12.875104},
abstract = {Retinal laser photocoagulation is an established treatment method for many retinal diseases like macula edema or diabetic retinopathy. The selection of the laser parameters is so far based on post treatment evaluation of the lesion size and strength. Due to local pigment variations in the fundus and individual transmission the same laser parameters often lead to an overtreatment. Optoacoustic allows a non invasive monitoring of the retinal temperature increase during retinal laser irradiation by measuring the temperature dependent pressure amplitudes, which are induced by short probe laser pulses. A 75 ns/ 523 nm Nd:YLF was used as a probe laser at a repetition rate of 1 kHz, and a cw / 532 nm treatment laser for heating. A contact lens was modified with a ring-shaped ultrasonic transducer to detect the pressure waves at the cornea. Temperatures were collected for irradiations leading to soft or invisible lesions. Based on this data the threshold for denaturation was found. By analyzing the initial temperature increase, the further temperature development during irradiation could be predicted. An algorithm was found to calculate the irradiation time, which is needed for a soft lesion formation, from the temperature curve. By this it was possible to provide a real-time dosimetry by automatically switching off the treatment laser after the calculated irradiation time. Automatically controlled coagulations appear softer and more uniformly.},
keywords = {AutoPhoN},
url = {http://dx.doi.org/10.1117/12.875104},
type = {Conference Proceedings}
}